This invention pertains to improved compression type self-sealing injection sites, and more particularly, it relates to a minimum size self-sealing injection sites or septums featuring self-sealing subsequent to puncture by a hypodermic needle or the like. The term "injection site" as used herein refers to self-sealing systems and similar bodies of the prior art used as ports and plugs. The injection sites of the invention have particular application in implantable prosthetic devices of the type which require filling through the site with a fluid by means of an injection needle or the like. For example, penile prosthesis, mammary prosthesis or tissue expanders devices having remote injection sites and drug delivery systems will make use of the improved injection sites of this invention. This invention was developed for use with a saline filled testicular prosthesis which is described herein. However, the injection sites of this invention can be used in any device requiring a plug or septum.
Injection sites, buttons and other self-sealing septums of the prior art using compression to self-seal are described in U.S. Pat. Nos. 4,428,364; 4,738,657; 4,798,584; 4,840,615; and 5,137,529.
The injection site of U.S. Pat. No. 4,428,364 contains multiple layers of fabric reinforced silicone rubber sheets fabricated into a dome shaped wall. The fabric weave within the layers is oriented in different directions. The reinforced silicone sheets are subjected to a swelling agent. The combined effect of the swelling silicone and restraining fabric causes a compressive stress to develop in the wall.
The injection sites described in U.S. Pat. Nos. 4,738,657, 4,798,584, and 4,840,615 are all generally similar. They use various bending and inverting techniques to create compressive stresses on the inside surface of the outer wall of the site. Compression is developed by (1) bending a sheet of silicone into a domed shape; (2) inverting a previously formed silicone dome; and (3) cutting the wall of a silicone tube then rolling it into a flat sheet.
Compression is attained in U.S. Pat. No. 5,137,529 through interference fits. An elastomeric septum formed with the outer housing is compressed by a rigid base member.
The prior art discussed above all develop enough compression to self-seal when subjected to hypodermic needle punctures. However, the prior art depends on other rigid members to maintain compression.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is "prior art" with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. .sctn.1.56(a) exists.